Technical Abstract:
During the ten years of the availability of commercial, transgenic crops, herbicide resistance has been the most important transgenically conferred crop trait. At this time, almost all of these crops are glyphosate-resistant soybean, maize, cotton, or canola. Bromoxynil-resistant crops are no longer on the market and glufosinate-resistant crops have a relatively small market share. Although the global acreage planted in these crops continues to increase, no new herbicide resistance genes and few new glyphosate-resistant crops are scheduled for introduction in the near future. Transgenes for the resistance to many herbicide classes have been patented, but very few of these are likely to be commercialized. Other approaches to using transgenes for weed management include the use of this technology to confer or improve allelopathic or competitive traits in crops and to improve the utility of weed biocontrol agents. The examples of genetic manipulation of the allelochemical levels in Sorghum Moench. spp. is discussed, as well as introducing virulence factors into mycoherbicide biocontrol agents. Lastly, the potential environmental benefits and risks of these technologies are considered.